crypto: authencesn - Fix src offset when decrypting in-place

crypto: authencesn - Fix src offset when decrypting in-place

commit 1f48ad3b19a9dfc947868edda0bb8e48e5b5a8fa upstream.

The src SG list offset wasn't set properly when decrypting in-place,
fix it.

Reported-by: Wolfgang Walter <linux@stwm.de>
Fixes: e02494114ebf ("crypto: authencesn - Do not place hiseq at end of dst for out-of-place decryption")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>